Stair Tracker Perception Using Temporal Edge Validation

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Solution Overview

Problem

Robots face challenges in traversing stairs due to the need for precise leg movement and foot placement, as they lack natural coordination and often generate poor sensor data, leading to inaccuracies in detecting stair features, especially during ascent and descent.

Innovation Solution

A stair tracker system that processes sensor data to detect and track stair features, generating a staircase model by identifying edges, walls, and heights, and refining these detections over time to improve accuracy and robustness in navigating stairs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If robots use sensor data to detect stair features, then they can navigate stairs, but the sensor data quality is poor leading to detection inaccuracies

Engineering Contradiction:
Improvestair feature detection accuracyVSAvoidsensor data quality
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system implements feedback by comparing detected edges across multiple time steps and using this temporal information to validate and refine stair feature detections. The feedback mechanism allows the system to identify consistent features across time steps and filter out spurious detections, thereby improving measurement precision despite poor sensor data quality.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary actions by detecting and tracking edges across multiple time steps before finalizing stair feature identification. By accumulating edge detection data over time and performing preliminary validation, the system prepares more reliable feature candidates for subsequent navigation decisions, improving overall detection accuracy.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If robots traverse stairs with precise leg movement, then navigation accuracy improves, but coordination complexity increases

Engineering Contradiction:
Improvefoot placement accuracyVSAvoidleg movement coordination
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system segments the stair traversal task into distinct phases: edge detection, feature identification, and execution. By breaking down the complex coordination problem into manageable segments with clear inputs and outputs, the system reduces the overall coordination complexity while maintaining foot placement accuracy through systematic processing at each stage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stair feature model serves as an intermediary between sensor data and leg movement control. This intermediate representation simplifies the coordination problem by providing a structured, validated description of stair geometry that the control system can use directly, reducing the complexity of translating sensor data into coordinated leg movements.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If the system processes sensor data over multiple time steps, then detection accuracy improves, but processing time increases

Engineering Contradiction:
Improveedge detection accuracyVSAvoiddata processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system applies partial action by processing only the most relevant features across time steps rather than analyzing all sensor data in full detail. By focusing computational resources on key edge detections and validated features, the system achieves improved accuracy without proportionally increasing processing time for the entire dataset.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The system uses periodic action by evaluating edge detections at discrete time steps rather than continuously processing all data. This periodic evaluation approach allows the system to accumulate sufficient information for accurate detection while maintaining a manageable processing节奏 that limits time loss.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentUS20230143315A1Perception and fitting for a stair tracker
Publication Date: 2023.05.11 BOSTON DYNAMICS INC
  • US20230143315A1 patent drawing
  • US20230143315A1 patent drawing
  • US20230143315A1 patent drawing

AI summary

A method for perception and fitting for a stair tracker includes receiving sensor data for a robot adjacent to a staircase. For each stair of the staircase, the method includes detecting, at a first time step, an edge of a respective stair of the staircase based on the sensor data. The method also includes determining whether the detected edge is a most likely step edge candidate by comparing the detected edge from the first time step to an alternative detected edge at a second time step, the second time step occurring after the first time step. When the detected edge is the most likely step edge candidate, the method includes defining, by the data processing hardware, a height of the respective stair based on sensor data height about the detected edge. The method also includes generating a staircase model including stairs with respective edges at the respective defined heights.